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ML66525 Family User’s Manual
Chapter 22
Special Function Registers (SFRs)
22 - 8
The meanings other than symbols in the Bit Symbol column are described below.
Blank
An I/O function register is assigned to this bit.
However, a bit symbol is not needed for this
bit because this bit does not have to be accessed in bits or cannot be accessed in bits.
(1)
An I/O function register is not assigned to this bit.
The write operation is ignored.
“1” is
always read from this bit.
(0)
Any write operation to this bit is ignored.
“0” is always read from this bit. “0” is read from
bits 10 to 15 of ADR00 to ADR07.
1
Be sure to write “1” to this bit.
0
Be sure to write “0” to this bit.
Initial value [H]
This value indicates the content of each SFR at reset (RESn signal input, BRK instruction
execution, overflow of watchdog timer, or opcode trap).
This value is expressed in hexadecial numbers.
(*1) Be sure to write “1” to bits 5 and 4 of ROMWIN.
(*2) Be sure to write “0” to bits 6 to 4 of ROMRDY.
(*3) Each flag of P5IO has the following functions. This is not the mode register for I/O switching
of port 5.
FSEL1 (bit 7), FSEL0 (bit 6):
These are flags for multiplication selection of PLL in the USB macro.
(0, 0) = x4, (0, 1) = x8, (1, 0) = x6, (1, 1) = prohibited
SCK4IO (bit 5):
This is an I/O switching flag for P10_3/SIOCK4 pin. It is also required to do I/O switching
through P10IO3. “0” = input, “1” = output
SCK4INV (bit 4):
This is a polarity selection flag for P10_3/SIOCK4 pin. “0” = positive, “1” = negative
STBSEL (bit 3):
This is an 80-system/68-system selection flag for secondary function output of P3_2/RDn pin.
“0” = 80-system, “1” = 68-system
MECKEN (bit 2):
This is a clock supply selection signal for Media control block.
“0” = clock supply, “1” = clock stop
UDCKN (bit 1):
This is a clock supply selection signal for USB DMA controller.
“0” = clock supply, “1” = clock stop
USBRST (bit 0):
This is a hardware reset control signal for USB macro.
“0” = USB reset, “1” = USB reset released
(*4) Bit 6 (NMIRD) of EXI2CON is a read-only bit. The write operation to this bit is ignored. “0”
is read from this bit.